1993 Audi 90 radiator fan runs continuously

My radiator fan recently started running after engine shut off. Today, it started running and now runs until thel battery is dead. When hooking up jumper cables, the fan starts up again before engine is started. I had the fan switch replaced about 4 months ago after the car overheated. It has recently started getting colder outside so perhaps coolant related?
Thanks,
Scott

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Friday, October 31st, 2008 AT 11:00 PM

13 Replies

RASMATAZ

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Check the cooling fan relay could be sticking closed -switch side

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Saturday, November 1st, 2008 AT 11:01 AM

LATCHKEY

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Ok - this may sound stupid but when I opened the relay box, it appears to be missing some of the relays - and specifically some of those relating to the cooling fan. I don't think anyone removed them recently either. Is it normal to have open spots? And when you say switch sides - can you be more specific? Thanks much.

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Saturday, November 1st, 2008 AT 2:07 PM

RASMATAZ

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Switch sides-means the switch side of the relay

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Saturday, November 1st, 2008 AT 2:20 PM

LATCHKEY

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Ok - so Ive located that panel. How would I know if the switch is stuck? #2 and #11 are empty. Or am I looking for another one on or near the radiator? I am a bit of a novice as you can see. :-)

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Sunday, November 2nd, 2008 AT 8:19 PM

RASMATAZ

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Remove the no.3 and 6 and see what happens

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Sunday, November 2nd, 2008 AT 9:28 PM

LATCHKEY

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So I pulled each one of them when the car was being jumped and kept coming back and forth testing different combinations, but the fan continued even when both the 3 and 6 were pulled - together and separate. I would have expected the fan to stop altogether at some point - with the switch removed yes?

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Monday, November 3rd, 2008 AT 9:08 PM

RASMATAZ

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The cooling fan circuit is shorted somewhere to a power source

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Monday, November 3rd, 2008 AT 10:50 PM

LATCHKEY

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Ok - so any idea how a novice would be able to fix that? Or should I bring it to a service center? Also, what should be the approximate cost to do so? Thanks for all your help.

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Tuesday, November 4th, 2008 AT 2:48 PM

RASMATAZ

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Sir-my adivse is bring her in to the pros this problem can be complicated for a DIY. As for the cost the flat rate labor varies with location could be $70.00-$130.00 per hr.

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Tuesday, November 4th, 2008 AT 2:54 PM

LATCHKEY

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Do you happen to have the wiring diagram for this model that I could see on this site? Also, is it possible that the run on fan switch needs replacing? Is there a way to test that?